With the Centre alerting three major cities, including Kolkata, against Taliban-trained terrorists, the security drill adopted after the 26/11 Mumbai attack was being maintained in the metropolis, its railway stations, airport and port, police said.

“Surveillance has been intensified on soft targets,” they said, with watch kept on the 21 entry points to the metropolis.

Vehicles are being checked and vigil kept on hotels, shopping malls, railway stations, airport, port and vital installations, they said.

Hoteliers have been asked to keep records of addresses and the purpose of the visit of all new guests.

Meanwhile, Captain A K Bagchi of the marine department of Kolkata Port Trust said that ‘level 2’ security drill was being maintained at the port as per the International Ships and Ports Security Act.

CISF personnel were in charge of security in the entire KoPT and Haldia dock areas, where all vessels were being checked and workers and labourers frisked while entering the port areas, Bagchi said.

CISF Commandant in-charge of security at the NSC Bose International Airport, Joyati Ghosh said security was stepped up after the central alert.

Meanwhile, railway officials said monitoring with CCTVs was being carried out at Howrah and Sealdah railway stations and Railway Protection Force asked to search all incoming and outgoing trains.

Control rooms have been opened in Sealdah and Howrah stations and at the divisional railway headquarters.